A heat exchanger arrangement for a vehicle heater, which has a heat exchanger housing of an essentially pot-like design, is known from EP 0 916 908 B1. An outer housing part of this heat exchanger housing is provided with an outer circumferential wall and with an outer bottom wall. An inner housing part of the pot-like heat exchanger housing has an inner circumferential wall and an inner bottom wall and is inserted into the outer housing part, so that it defines, together with this, a heat carrier medium flow space. At the end area of the inner housing part located at a distance from the outer bottom wall or the inner bottom wall, said inner housing part is provided with an essentially ring-shaped outer circumferential wall section, which surrounds the inner circumferential wall, is connected to the inner circumferential wall in the axial end area thereof and to which the outer circumferential wall of the outer housing part is connected in a fluid-tight manner. This outer circumferential wall section defines, together with the section of the inner circumferential wall located in the same axial area relative to a longitudinal axis of the pot-like heat exchanger housing, a ring-like intermediate space, which provides a part of the heat carrier medium flow space and is not closed in the radially outward direction by the outer circumferential wall of the outer housing part.
A waste gas flow connecting piece is provided at the inner housing part in the axial area of the outer circumferential wall section, i.e., in the axial area in which the ring-like intermediate space forming one part of the heat carrier medium flow space is formed. This waste gas flow connecting piece passes through the ring-like intermediate space and is open through the inner circumferential wall defining the ring-like intermediate space in the radially inward direction towards an interior space of the heat exchanger housing, which said interior space is surrounded by the inner wall. In case of integration in a vehicle heater, combustion waste gases flow through this interior space of the heat exchanger housing, so that the inner heat exchanger housing can absorb heat from the combustion waste gases and can transfer this to heat carrier medium flowing in the heat carrier medium flow space, i.e., for example, water. The combustion waste gases leave this interior space through the waste gas flow connecting piece passing through the ring-like intermediate space between the outer circumferential wall section and the inner circumferential wall.
Heat carrier flow connecting pieces, which are open towards the heat carrier medium flow space and thus make possible the feeding and removal of heat carrier medium into and from the heat carrier medium flow space, are provided at the outer circumferential wall of the outer housing part where the latter adjoins the outer bottom wall. The heat carrier medium flow connecting pieces are located, for example, in the same circumferential area as the waste gas flow connecting piece provided at the inner housing part.